Re: Recommendations for a ?real RAID" 1 card on Centos box

["nate" <centos@xxxxxxxxxxxxxxxx>]

Karanbir Singh wrote:
> Therese Trudeau wrote:
>> I'm just really looking for a RAID card that will do RAID 1, with four
>> drive capacity, i.e.,
>> a master drive with the OS and applications installed and mirrored, and a
>> slave drive for data and
>> photos, graphic design, video, etc also mirrored.  What would battery
>> built into a RAID card
>> do for me?
>
> the whole point of a BBU is that you can turn on write back caching -
> and get a fair win in write performance on regular tasks.

You can turn on write back caching if you have a UPS as well
(provided your UPS is wired into your system for a graceful shutdown)

I've never noticed any data loss from write cache being enabled on
a 3ware card that didn't have a BBU. Not to say that BBU is a not
a good idea in any case. Of the ~400 3Ware cards I've used(90% of
them being 8006-2), only a handful have had a BBU. But all of them
were backed either by a basic UPS or a full UPS with generator
backup. I haven't run a computer without a UPS since 1996 ? It's
second nature these days I don't even remember to recommend them
anymore.

Of course I may of had data loss, but in the past 8 years it's not
been anything that I've personally noticed.

I'm not sure if all 3Ware models support BBU or not.

For anything real serious like I prefer bigger dedicated storage
systems, my array of choice these days comes from 3PAR (entry level
pricing ~$90k), really makes my job easy and stress free.

nate

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